March 2008

Red Dwarfs: Dust, Details and Habitability

March 31, 2008

Budding astrobiologists should be thinking about the significance of red dwarf stars as they approach their careers. Let’s say, as pure speculation, that one out of every thousand stars in class M has a planet in the habitable zone. That works out to 75 million potentially habitable planets around these stars in our galaxy alone. [...]

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Notes & Queries 3/29/08

March 29, 2008

Did short supplies of oxygen and molybdenum slow down the evolution of animal life? Ancient oceans low on molybdenum would create problems for bacteria that use the element to convert atmospheric nitrogen into a form useful for living things. Brian Wang muses over these matters in his entry in the latest Carnival of Space, referring [...]

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Intriguing Temperatures on Enceladus

March 28, 2008

Cassini’s recent pass through the plumes of Enceladus resulted in a number of intriguing finds, perhaps the most interesting of which is the temperature along the ‘tiger stripes.’ These are the fissures from which Enceladus’ famous geysers erupt. Cassini’s Composite Infrared Spectrometer found them to be warm along almost their entire length, reaching no less [...]

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Life’s Precursors: The Interstellar Connection

March 27, 2008

Was the early Earth seeded with amino acids from deep space? The variety of molecules found between the stars makes the supposition provocative, but finding interstellar amino acids has been a challenge. Various amino acids have indeed been found in meteorites, but it has been argued that these could have been produced right here in [...]

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TESS: All Sky Survey for Transiting Planets

March 26, 2008

I’ve never met George Ricker, but in at least one respect I believe he thinks the way I do. Ricker is senior research scientist at MIT’s Kavli Institute for Astrophysics and Space Research, and he’s someone who can connect the exoplanetary systems we study with places we might eventually go. As witness this comment in [...]

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Death and Life in a Distant Galaxy

March 25, 2008

By Larry Klaes One response to Fermi’s famous ‘Where are they?’ question is to speculate on factors that might destroy incipient life forms. The recent gamma ray burst seen halfway across the universe reminds us of the powers that can be unleashed within a galaxy. Now Tau Zero journalist Larry Klaes goes to work on [...]

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Musings on Titan’s Sub-Surface Ocean

March 24, 2008

The recent news that there may be an underground ocean on Titan tantalizes us in astrobiological terms. It also brings us up against the question of how to define a habitable zone. The standard definition involves the presence of liquid water at the surface, a reasonable requirement when you’re looking for carbon-based life. But it’s [...]

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GRB Visible Halfway Across the Universe

March 21, 2008

The recent news of a record-setting gamma ray burst (GRB) in a distant galaxy doesn’t just raise eyebrows. It practically singes them. Occurring in the midst of a 24-hour period that saw five gamma ray bursts (a story in itself), the burst called GRB 080319B was picked up by the Swift satellite on March 19 [...]

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Organic Molecule in Exoplanet Atmosphere

March 20, 2008

Well-studied HD 189733b is a Jupiter-sized planet again in the news. Studying this transiting world, scientists using Hubble Space Telescope data have made the first identification of an organic molecule — methane — in the atmosphere of an exoplanet. What’s particularly significant here is the growing sophistication of our use of spectroscopy, splitting light into [...]

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Starships, Pubs and Sir Arthur

March 19, 2008

I’m a great believer in getting back to work when bad news hits, and I suspect Arthur C. Clarke was as well. His almost 100 books surely attest to the fact. With intriguing exoplanet news about to be released, that is exactly what I’ve been doing this morning, with an article I’ll post tomorrow. As [...]

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